Dental imaging apparatus

ABSTRACT

The invention relates to a dental imaging apparatus which includes an x-ray imaging means and at least one color camera for photographing the face of a patient positioned at the imaging station of the apparatus, which at least one color camera is arranged to image the patient&#39;s face positioned at the patient support station from different directions, and means arranged into functional connection with said at least one color camera for creating a virtual three-dimensional texture model of the patient&#39;s face.

FIELD OF INVENTION

The invention relates to a dental imaging apparatus according to thepreamble of claim 1.

BACKGROUND OF INVENTION

The history of medical x-ray imaging originates approximately to thetime of inventing x-radiation. For more advanced ways of imaging, e.g.the development of panoramic x-ray imaging in the dental field startedfor over a half century ago. The development of digital imagingespecially in the 1990s brought digital x-ray imaging devices also todental practices. The latest development step in the dental field hasbeen the generalisation of the cone-beam computed tomography apparatusdesigned for three-dimensional imaging of skeletal structures of thecranial area. Concerning new possibilities offered by them, worthmentioning is e.g. applications related to implant attachment and othertreatment planning.

Along with the development of cameras and information technology, suchas that of computing power of computers, it has become possible tocreate virtual three-dimensional surface models of different surfaces.In the dental field, facial surface models can be utilised e.g. inconnection with orthodontic treatment, as orthodontic treatment can alsohave an effect on facial shapes. Such surface models have sometimes beencombined with information on surface texture, i.e. that of details ofthe surface/surface structure.

The prior art also includes techniques to create a virtualthree-dimensional texture model without a separately created model ofthe three-dimensional shape of the surface.

Among others, the need for acquiring a separate device for a particularimaging purpose has been limiting utilisation of facial texture modelsin the dental field. Acquiring a separate device is not only a questionof costs but also of space, as each device always requires a space to beinstalled and/or stored in and/or where it can be used. On the otherhand, each separate imaging always takes a certain amount of time, too.Furthermore, as far as data processing is concerned, there are certainchallenges in the arrangements in which creating the model requirescombining image information acquired at different times, imageinformation acquired by different imaging devices and/or imageinformation acquired of an anatomy having been positioned in differentways for imaging.

BRIEF DESCRIPTION OF INVENTION

The object of the invention is a versatile dental imaging apparatus, bymeans of which it is possible to create for the virtualthree-dimensional modelling of a patient's skull at least x-ray imageinformation on the patient's cranial skeletal structure and, further,information on the colours, scars, hair, moles etc. of the patient'sface. The apparatus according to the invention includes means forproducing not only x-ray images but also three-dimensional imagescomprising a facial surface texture. Preferably, the apparatus isarranged to enable creating 3D images on the cranial skeletal structureand/or teeth and, with the same patient positioning and imaging event,information on facial soft-tissue surface shapes and surface texture.Essential characteristics of the invention are defined in more detail inthe accompanying patent claims.

The invention introduces a new arrangement for versatile modelling ofthe patient's cranial anatomy. The invention enables, among others,using existing imaging devices and avoiding the need to use prior-artspecial arrangements, which lowers the dentists' threshold to employ thepossibilities offered by virtual 3D models.

Next, the invention and its preferable embodiments will be described inmore detail also with reference to the enclosed figures.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows one imaging apparatus according to the invention, the basicstructure of which includes a base construction and an arm partsupporting imaging means.

FIG. 2 shows a receiver module of image information applicable for usein the apparatus according to FIG. 1.

FIG. 3 shows directing of laser beams from the module according to FIG.2 towards a patient positioned at an imaging station.

FIGS. 4a and 4b show signal paths according to one preferable embodimentof the invention from an x-ray detector and at least one colour cameravia a frame grabber to a computer.

FIGS. 5a-5c show examples on various virtual three-dimensional facialmodels.

FIG. 6 shows a principle according to one preferable embodiment of theinvention for controlling certain operations of the apparatus.

DETAILED DESCRIPTION OF INVENTION

FIG. 1 shows one imaging apparatus according to the invention. Theapparatus includes a vertical support construction (11) from whichhorizontally extends an arm (12) supporting a patient support means andan arm part (13) which supports a structure supporting imaging means ofthe apparatus, an arm part (14). The arm part supporting the imagingmeans (14) may be arranged rotatable. To the arm part supporting theimaging means (14) are arranged at a distance from each other an x-raysource (15) and a receiver of x-ray image information (21), which arelocated at the apparatus with respect to a patient support means (17)such that an imaging station (18) is created to the apparatus which islocated between the x-ray source (15) and the receiver means of x-rayimage information (21) such that a beam produced by the x-ray source(15) can be directed to go through said imaging station (18) towards thereceiver means of x-ray image information (21). The apparatus includescontrol means, of which FIG. 1 shows a control panel (16) arranged tothe support construction (11) and operating mode selection means (19)pertaining in it. In the apparatus according to FIG. 1, the receivermeans of ray image information (21) are arranged as part of a receivermodule of image information (20) which is arranged into connection witha computer (30) via a cable. A means for processing image information isarranged to the computer, and a display (31) to present images createdby the computer.

FIG. 2 shows a receiver module of image information (20) applicable foruse in the apparatus according to FIG. 1. The module includes two colourcameras (22) arranged horizontally on opposite sides of the x-raydetector (21) and aligned at the imaging station (18). Further, lightsources (23) preferably producing white light to illuminate the imagingstation (18) and two lasers (24) are arranged to the module (20). Theselasers are positioned substantially in the middle of the module (20) tothe substantial proximity of its upper and lower edges. The lasers (24)are arranged to emit and direct at the imaging station (18) a narrowvertical planar fan beam which casts a laser light pattern on thepatient's face. FIG. 3 shows how the laser fan beams produced by the twolasers (24) shown in FIG. 2 can be directed at the imaging station (18)to cover the patient's face in the vertical direction without shadowareas.

The invention can employ two lasers (24) of the same colour or they maybe of different colour, i.e., the first can be arranged to produce laserlight of a first and the other of a second colour. When using lasers ofthe same colour, it can be challenging to implement the structure inpractice such that the lasers (24) produce exactly overlapping beams.This can already be difficult from the viewpoint of manufacturingtechniques and, further, alignment problems may also occur later on whenusing the device. As regards to lasers of different colours, they can bearranged to point at different directions and can be identified in theimage e.g. by machine vision based on searching the image for the huesin question. If the mutual alignment of the lasers of different colourschanges during use, instead of realigning the lasers (which couldrequire service at the factory), it is possible to fix the situation byrecalibration.

The light sources (23) arranged to the apparatus can be arranged toproduce lights of other colour or colours than white, too. Diffusingfoils may be arranged in front of the light sources (23) (cf. surface(23) in FIG. 2), whereby light is emitted from a larger area andsubstantially evenly and illumination in the target area will be even.Furthermore, the light sources (23) may be provided with polarizers (cf.surface (23) in FIG. 2) which can eliminate mirror reflection from theskin surface possibly otherwise visible in the image of the secondcamera, caused by the light source located in connection with the firstcamera, and vice versa. It is also possible to arrange to the apparatusmore than two or only one colour camera (22), and the cameras or camera(22) can be arranged to operate not only as a photographic camera butalso as a continuously-operating video camera. The light pattern to bedirected on the patient's face can be produced by some other lightsource than a laser and the colour of this light pattern, too, can bearranged changeable and, even when produced by a laser, its colour canbe some other than the conventional red, such as preferably particularlygreen.

When the structure supporting the imaging means (14) of the apparatusaccording to FIG. 1 is arranged rotatable, it is possible for the one ormore colour cameras (22) arranged to the receiver module of imageinformation (20) to shoot images from the patient's face positioned atthe imaging station (18) from different directions. Then, it is alsopossible to make the laser light pattern to scan the patient's face.When using e.g. the arrangement according to FIG. 2, in which the camera(22) and the laser (24) are positioned at a distance from each other, itis possible to scan the patient's face positioned at the imaging station(18) with the laser line and, at the same time, to shoot images of theface at an angle (at an angle of less than 90 degrees) with respect tothe direction of the laser beam. Of the image information acquired thisway, it is possible to produce a three-dimensional surface model of thepatient's facial shape. In one preferable embodiment of the invention,the control system of the apparatus is provided with a control functionto always momentarily switch off the laser for a desired duration duringa scan, during which periods it is possible to shoot colour images ofthe patient's face without the laser light pattern and to produce fromthe hence acquired image information a texture model of the patient'sface. However, it is in principle possible to operate also such that thelaser is not switched off at all but the laser line is removed from thetexture model being formed during processing of the image informationproduced in the imaging programmatically.

FIG. 4a shows a signal path from the receiver module of imageinformation (20) to the computer (30) used in one preferable embodimentof the invention. The signal path of image information detected by thecolour camera or cameras (22) and the x-ray detector (21) to thecomputer (30) can be arranged shared such that the image informationacquired from them is directed to the computer (30) via the same oneframe grabber. Preferably, a signal path is also arranged in theapparatus at least between the control means of the movements of theimaging means and/or the control means of the x-ray source and thecomputer via the same Ethernet cable as the signal path from the camerato the computer. This can be implemented e.g. by means of anEthernet-HUB component or an Ethernet switch component arrangeable tothe apparatus. FIG. 4b shows another preferable embodiment for arrangingsignal paths to the apparatus which also requires only one Ethernetcable between the imaging means and the computer.

The means arranged to the computer (30) to process image informationacquired when imaging the patient's face arranged at the imaging station(18) comprise, according to the invention, an algorithm for processingat least image information acquired from the x-ray detector (21) and forprocessing image information acquired from the colour camera or cameras(22) to create a virtual three-dimensional texture model of thepatient's face. The texture model can be produced either solely of thephotography information picturing the patient's face from more than onedirection, or its production can utilise e.g. information on the shapeof the surface of the soft-tissue of the patient's face acquired whenx-ray imaging the patient. In a preferable embodiment of the invention,the image processing means includes a means for creating a facialsurface model from the image information of the laser line directed onthe patient's face, which information can be utilised in producing thethree-dimensional texture model of the patient's face. Preferably, theimage processing means includes a means which can produce models whichsimultaneously show three-dimensionally both the facial texture and atleast parts of the teeth and/or skeletal structure of the patient'scranial area.

FIG. 5a shows an example of a facial three-dimensional modelimplementable with the apparatus according to the invention in which tothe facial texture model is integrated information on the skeletalstructure and teeth of the cranial area of the patient. FIG. 5b againshows an example of a facial surface model produceable with theabove-described apparatus according to the invention, and FIG. 5c adifferent projection of the model according to FIG. 5b , which isproduced only of information acquirable from the laser line patterns onthe patient's face. Comparing FIGS. 5b and 5c illustrates how the facialtexture model produceable with the apparatus according to the inventiondiffers from a mere facial surface model.

FIG. 6 shows a diagram which illustrates a principle according to whichcertain operations of the apparatus according to the above-describedembodiment can be controlled. In the figure, the imaging of thepatient's face is assumed to be implemented—simultaneously with x-rayexposure or as its own imaging—such that the arm part supporting theimaging means (14) is made to rotate such that the receiver module ofimage information (20) moves from one side of the patient's face to theother for at least 180 degrees, such as for at least 200 degrees, suchas for about 260 degrees. During this motion, the patient's face isilluminated by regularly pulsing the light sources (23) of the receivermodule of image information (20), whereas the laser light is otherwisekept continuously on but, during the scan, it is momentarily switchedoff in order to be able to shoot images from the face of the patientpositioned at the imaging station (18) also without the laser lightpattern. The operations of the apparatus are synchronised to comprisetwo kinds of periods; during the first of which the laser light isswitched off and images are shot of the face during such sequences ofthe light pulses whereby the patient's face is illuminated, and duringthe second periods the laser light is again kept on whereby the laserline, when the arm part supporting the imaging means (14) rotates, movesalong the patient's face and images are shot of the face during suchperiods of the light pulses whereby the patient's face is notilluminated. When the imaging employs two colour cameras (22) accordingto the embodiment of the invention described above, concerning theoperation mode shown in FIG. 6, the control as described above isimplemented such that the first and the second camera (22) shoot imagesalways during successive light pulses. The image information integratedby the cameras (22) can be read out always during those periods of thelight pulsing when image information is not being integrated.

The diagram of FIG. 6 thus shows one principle applicable for use in theinvention. However, if desiring to prevent the patient positioned at theimaging station from sensing the flickering of lights caused by thepulsing of facial illumination, the pulse frequency of the illuminationmust be arranged to be at least 50-60 Hz. Such pulsing would lead, whenoperating exactly the way shown in FIG. 6, to an unnecessarily largeamount of image information for practical implementation of theinvention. The above principle can indeed be applied e.g. such that,during the above-described periods, the first and the second camera donot shoot images during each light pulse but only e.g. at times of theorder of every tenth pulse, whereby there also is more time for readingthe image information from the camera.

Thus, in one preferable embodiment of the invention, the means forilluminating the patient's face is controlled to illuminate thepatient's face in short pulses, preferably at least at the frequency of50-60 Hz, the laser or lasers are controlled to produce a laser lightpattern on the patient's face otherwise continuously but such that thereare periods during the rotation of the arm part, such as less than 10periods, during which no laser light pattern is produced, and the colourcamera or cameras are controlled to shoot images at the first pulsesteps when the laser light pattern is directed on the face and when themeans for illuminating the patient's face do not illuminate the face,and at the second pulse steps whereby no laser light pattern is directedon the face and when the means for illuminating the patient's face doilluminate the face.

One practical way to implement sequencing of shooting images accordingto the practical mode of operation described above comprisesimplementing the first and the last period during movement of theimaging means as periods during which the face is imaged without a laserline and for the duration of the movement in question, this kind ofperiods are arranged for the total of five at even intervals. Accordingto such an embodiment of the invention, for the total of ten colourimages of the patient's face would thus be shot from differentdirections without the laser light pattern, and the angular velocity ofthe motion of the imaging means from one side of the patient's face tothe other can be arranged such that during the four periods fallingbetween these periods, images of the order of 300 are shot of the laserlight line directed on the face. It is still evident to those skilled inthe art that it is e.g. not necessary to shoot images of the laser lightpattern at even intervals and that their number, and the positions fromwhich images of the laser line are shot, may be varied e.g. according tothe desired horizontal resolution of the surface construction. It isalso not necessary to shoot photographs without the laser line at evenintervals and their number and position can be varied according to anyparticular need as well so that suitable joining points and adequatecoverage are achieved for creating a three-dimensional texture modelfrom the partial facial images shot from different directions.

The apparatus according to the invention and its operation modeselection switch (19) can be arranged to enable x-ray imaging andimaging of the patient's face to occur either separately or, in onepreferable embodiment of the invention, to be implemented in connectionwith the same imaging event, even simultaneously. Photographing the facefrom different directions simultaneously with the x-ray imagingeliminates a need for a separate imaging whereby, among other things,there is no need to calibrate some other imaging device and to positionthe patient to this other device for a separate facial imaging. Thus,trouble and time are saved when the facial imaging can be performedsimultaneously with the x-ray imaging. Also, if one wishes to integrateimage information acquired in different ways of imaging, e.g. to bepresented in the same three-dimensional model, the combining is theneasier as the imaged anatomy has been in the same position and in theset of coordinates according to the same imaging device when imaged. Theapparatus enables the use of the laser line to enhance bringing out thefacial shapes in more detail by transferring the location of the laserline on the face, by shooting profiles produced by the laser line on thefacial surface and by calculating the shape of the facial surface fromthese profiles.

Above, the invention has been described predominantly with reference tothe enclosed figures, but all of the above-described details of theembodiments of the invention are not necessary or the only ones possibleconsidering implementing the invention. The number of colour camerasused in the apparatus can be some other than two and, if the apparatusenables changing the camera location with respect to the imagingstation, it is possible to shoot images of the patient's face fromdifferent directions even with one camera. In a preferable embodiment ofthe invention, the apparatus is arranged with a lighting arrangementemitting white light to illuminate the patient's face, which isadvantageous considering imaging the facial hues, but it is possible toconsider the invention being also utilisable without one or severalsources of white light integrated in the apparatus and also with lightsof other colours. Furthermore, adequate information for producing athree-dimensional facial texture model can be acquired only fromphotographing the face from different directions, but the preferableembodiments of the invention also utilise e.g. information on the shapesof the facial soft-tissue surface acquired from an x-ray imaging, orinformation on the facial surface shapes available from a laser scan ofthe face.

The receiver module of image information applicable for use in theapparatus can according to the embodiment of above comprise the receiverof x-ray image information (21) arranged substantially in the middle ofthe module, seen from the horizontal direction, and two lasers (24), andarranged substantially at opposite ends of the module (20) on the onehand a first and a second colour camera (22), on the other hand a firstand a second lighting structure (23). When viewing the module (20) inthe vertical direction, it may comprise an arrangement in which saidlasers (24) are arranged substantially at the edges of the receivermodule of image information (20), and said lighting structures (23) todirect light at the imaging station (18) from above and from below saidcolour cameras (22). The functionality according to the invention formodelling at least part of the face can nevertheless be considered to beachieved with other kinds of arrangements as well, such as with anarrangement which uses two light lines and only one camera.

The colour camera pertaining to the apparatus according to the inventioncan also be used for other purposes than those described above. Thecamera or cameras can be arranged to operate as a video camera, wherebyit is possible to e.g. monitor and/or save the patient's expressions andpossible movements before the x-ray imaging and/or during exposure, withsuitable arrangements also in 3D. In the above embodiments, the colourcamera or cameras are located to the arm part supporting the imagingmeans to the substantial proximity of the x-ray detector, but the colourcamera or cameras can also be arranged e.g. to the substantial proximityof the x-ray source. Generally, it is advantageous to position thecolour camera or cameras, as well as the laser or lasers possiblypertaining to the apparatus, to such structure of the apparatus which isalready arranged movable with respect to the imaging station for thepurposes of x-ray imaging by the apparatus.

The computer pertaining to the apparatus does not have to be aphysically separate device from the imaging means but it can also beintegrated as part of the actual imaging device.

The x-ray imaging means of the apparatus preferably enable computedtomography imaging, especially cone-beam computed tomography imagingknown to be used in the dental field, the paths of the arm partsupporting the x-ray imaging means used in which apparatus are typicallyarranged to enable rotation of the arm part with respect to astationary, virtual vertical axis going through the imaging station,which motion is also directly utilisable for producing image informationfor creating a three-dimensional facial texture model.

This property of the imaging apparatus makes implementation ofespecially the facial laser scanning quite simple, as the x-ray imagingapparatus already includes means to implement movements applicable foruse in laser scanning. The laser scanning can in many casessignificantly facilitate detection of three-dimensional surface shapesof the patient's face as compared to using information acquired solelyfrom colour photography of the face. In a preferable embodiment of theinvention, there is then e.g. an arrangement in which said receivermeans of x-ray image information (21) comprise a detector, thedimensions of the area receiving image information of which are at leastof the order of centimeters, said structure supporting the imaging means(14) being arranged to be rotatable with respect to a vertical, virtualrotation axis going through a stationary imaging station (18) such thatthe x-ray source (15) and the receiver means of x-ray image information(21) move on opposite sides of the imaging station (18), in which thecontrol system of the apparatus comprises a control routine, which onthe one hand controls the rotating motion of the structure supportingsaid imaging means (14), the x-ray source (15) and the receiver means ofx-ray image information (21) to produce image information, of which withsaid means for processing information (30) detected by the receiver ofx-ray image information (21) can be reconstructed a three-dimensionalx-ray image, and on the other hand, controls at least said colour camera(22) to shoot colour images of the face of a patient positioned at theimaging station (18) during said rotating motion, and in which the imageinformation processing means (30) functionally pertaining to theapparatus are arranged to create a three-dimensional model presentableon the display (31) of the patient positioned at the imaging station(18), which model shows at least a portion of the skeletal constructionand/or teeth of the patient's cranial area and at least a portion of thetexture of the patient's facial area.

According to one preferable embodiment of the invention, the apparatusincludes a means for realizing the imaging such that the computedtomography imaging is implemented with a rotation angle of about 200degrees and the photography with a rotation angle of about 260 degrees.In practice, this can be then implemented such that one manoeuvre of 260degrees is made, during which the x-ray imaging is started after amovement of 30 degrees and correspondingly stopped earlier than thephotography, or by first picking up x-ray image information during amanoeuvre of about 200 degrees in a first direction, continuing themovement in this first direction to the starting position ofphotography, and implementing photography during a manoeuvre of 260degrees occurring in the opposite direction. An advantage of the latteralternative is that the motion during mere photography can beimplemented as fast (i.e. with higher angular velocity than the x-rayimaging) without the velocity needed in computed tomography imaginglimiting the angular velocity, which decreases the risk of the patient'sexpression changing or of other motions during exposure.

The invention claimed is:
 1. A dental imaging apparatus, which apparatusincludes a support construction (11, 13) for supporting a structuresupporting imaging means (14), at least one imaging station (18) forplacing a patient to the apparatus for imaging, in which apparatus theimaging means includes at least an x-ray source (15) and a means forreceiving x-ray image information (21), which have been arranged in theapparatus in such a way with respect to said imaging station (18) thatthe x-ray source (15) and the means for receiving x-ray imageinformation (21) can be positioned at opposite sides of the imagingstation (18) such that a beam generated by the x-ray source (15) can bealigned to go through said imaging station (18) and towards said meansfor receiving x-ray image information (21), a control system forcontrolling operations of the imaging apparatus and a means integratedwith the imaging apparatus or arranged into functional connection withit for processing information detected at the receiver of x-ray imageinformation (21), wherein the apparatus includes a means forphotographing (22) a patient's face and/or for producing a movingpicture of the patient's face from at least two directions while thepatient is positioned at said imaging station (18), which meanscomprises at least one colour camera (22) the location of which withrespect to said imaging station is arranged changeable and/or at leasttwo colour cameras being arranged to image the patient's face positionedat the patient support station (18) from different directions, at leastone lighting structure (23) to illuminate the patient's face positionedat the imaging station (18), and a means arranged into functionalconnection with said at least one colour camera (22) for processing theimage information acquired when imaging the patient's face to create avirtual three-dimensional texture model of the patient's face, and/orfor combining the image information detected by said at least one colourcamera (22), or the three-dimensional texture model created from it, toa surface model of the patient's face to create a virtualthree-dimensional texture model of the patient's face.
 2. The imagingapparatus according to claim 1, wherein the apparatus includes a meansfor creating a virtual model which comprises x-ray image information atleast from a portion of the bones and/or teeth of the patient's cranialarea integrated with said virtual three-dimensional texture modelproduced of the patient's face.
 3. The imaging apparatus according toclaim 1, wherein the control system of the apparatus comprises a meansfor implementing the x-ray imaging and the imaging of the patient's faceat the same time and/or as a combined imaging taking place during oneimaging event, and/or the control system of the apparatus comprises aselection means for implementing the x-ray imaging and the imaging ofthe patient's face either with at least one of the above ways or forimplementing at least one of said imagings as a separate imaging.
 4. Theimaging apparatus according to claim 1, wherein said at least onelighting structure (23) and/or at least one colour camera (22) isarranged to the apparatus such that the patient's face can beilluminated and imaged from different directions when the patient ispositioned at said imaging station (18) arranged for x-ray imaging. 5.The imaging apparatus according to claim 1, wherein said lightingstructure (23) is arranged to comprise a lighting structure whichdirects light towards the patient's face arranged at the imaging station(18) substantially from above or from below said at least one colourcamera (22).
 6. The imaging apparatus according to claim 1, wherein theapparatus includes at least two colour cameras (22) and they arearranged to be located horizontally at a distance from each other. 7.The imaging apparatus according to claim 1, wherein the control systemof the apparatus includes a means for controlling said lightingstructure (23) to produce white light, to produce pulsed white lightand/or to produce lights of different colours.
 8. The imaging apparatusaccording to claim 1, wherein the apparatus includes at least two colourcameras (22) and at least two lighting structures (23) arranged inconnection with said at least two colour cameras 122) to direct lighttowards the face of the patient positioned at the imaging station (18)substantially from above and from below of at least two colour cameras(22).
 9. The imaging apparatus according to claim 1, wherein saidlighting structure (23) and at least one colour camera (22) are arrangedinto connection with said structure supporting the imaging means (14).10. The imaging apparatus according to claim 9, wherein said structuresupporting the imaging means (14) is arranged rotatable with respect toa vertical virtual axis going through the patient support station orsome other virtual vertical axis.
 11. The imaging apparatus according toclaim 9, wherein structures, components and control means of theapparatus related to x-ray imaging are arranged to enable dentalpanoramic imaging, dental computed tomography imaging and/or dentalcone-beam computed tomography imaging.
 12. The imaging apparatusaccording to claim 1, wherein said structure supporting the imagingmeans (14) is arranged rotatable with respect to the imaging station(18) for at least 180 degrees and the control system of the apparatus tocontrol said at least one colour camera (22) to shoot at least twocolour images of the patient's face positioned at the imaging station(18) within the angle range in question.
 13. The imaging apparatusaccording to claim 1, wherein information detected by said receiver ofx-ray image information (21) and at least one colour camera (22) isarranged to be directed to the same one frame grabber, and/or via thesame one Ethernet cable from the imaging device to physically separatemeans for processing image information (30).
 14. The imaging apparatusaccording to claim 1, wherein the apparatus includes a means integratedin it or brought to functional connection with it for creating athree-dimensional surface model of the patient's face.
 15. The imagingapparatus according to claim 1, wherein said means for receiving x-rayimage information (21) comprises a detector, the dimensions of the areareceiving image information of which are at least on the order ofcentimeters, said structure supporting the imaging means (14) isarranged to be rotatable with respect to a vertical, virtual rotationaxis going through the stationary imaging station (18) such that thex-ray source (15) and the receiver means of x-ray image information (21)move on opposite sides of the imaging station (18), in which the controlsystem of the apparatus comprises a control routine, which on the onehand controls a rotating motion of the structure supporting said imagingmeans (14), the x-ray source (51) and the means for receiving x-rayimage information (21) to produce image information, with which saidmeans for processing information (30) detected by the means forreceiving x-ray image information (21) can reconstruct athree-dimensional x-ray image, and on the other hand controls at leastsaid colour camera (22) to shoot colour images of the patient's facepositioned at the imaging station (18) during said rotating motion, andthat the image information processing means (30) functionally pertainingto the apparatus are arranged to create a three-dimensional model of thepatient positioned at the imaging station (18) which is presentable on adisplay (31), which model shows at least a portion of the bones and/orteeth of the patient's cranial area and at least a portion of thetexture of the patient's facial area.
 16. The imaging apparatusaccording to claim 1 wherein the apparatus includes at least twolighting structures (23) in front of which is arranged a diffusing foiland/or a polarizer.
 17. A dental imaging apparatus, which apparatusincludes a support construction (11, 13) for supporting a structuresupporting imaging means (14), at least one imaging station (18) forplacing a patient for imaging, in which apparatus the imaging meansincludes at least an x-ray source (15) and a means for receiving x-rayimage information (21) which have been arranged in the apparatus in sucha way with respect to said imaging station (18) that the x-ray source(15) and the means for receiving x-ray image information (21) can bepositioned at opposite sides of the imaging station (18) such that abeam generated by the x-ray source (15) can be aligned to go throughsaid imaging station (18) and towards said means for receiving x-rayimage information (21), a control system for controlling operations ofthe imaging apparatus and a means integrated with the imaging apparatusor arranged into functional connection with the imaging apparatus forprocessing information detected at the receiver of x-ray imageinformation (21), wherein the apparatus includes a means forphotographing (22) a patient's face and/or for producing a movingpicture of the patient's face from at least two directions while thepatient is positioned at said imaging station (18), which meanscomprises at least two colour cameras (22) the location of which withrespect to said imaging station is arranged changeable or at least twocolour cameras being arranged to image the patient's face positioned atthe patient support station (18) from different directions, the colourcameras (22) being arranged to the substantial proximity of the x-raysource (15), and a means arranged into functional connection with saidat least two colour cameras (22) for processing the image informationacquired when imaging the patient's face to create a virtualthree-dimensional texture model of the patient's face, and/or forcombining the image information detected by said at least two colourcameras (22) or the three-dimensional texture model created from it, toa surface model of the patient's face to create a virtualthree-dimensional texture model of the patient's face.
 18. The imagingapparatus according to claim 17, wherein at least two colour cameras(22) are arranged to be located horizontally at a distance from eachother.
 19. The imaging apparatus according to claim 18, wherein theapparatus includes at least one lighting structure (23) to illuminatethe patient's face positioned at the imaging station (18), and saidlighting structure and the cameras (22) being arranged into connectionwith said structure supporting the imaging means (14).
 20. The imagingapparatus according to claim 19, wherein said structure supporting theimaging means (14) is arranged rotatable with respect to a verticalvirtual axis going through the patient support station or some othervirtual vertical axis.
 21. The imaging apparatus according to claim 20,wherein structures, components and control means of the apparatusrelated to x-ray imaging are arranged to enable dental panoramicimaging, dental computed tomography imaging and/or dental cone-beamcomputed tomography imaging.